Firearm



C. H. BARNES Feb. 8, 1944.

FIREARM Filed March 18, 1941 AGENT Patented Feb. 8, 1944 TENT ortica FIREARM Charfles H. Barnes, Bridgeport, Conn., assigner lto Remington Arms Company, Inc., a corporation yci? Delaware Application Mai-c1118, 1941, serial No. ceases 4 Claims.

This invention relates to rearms and in particular to firearms having Ygas operated breech blocks.

An object of this invention is to 'provide an improved mechanism fo'r converting 'a manually operated firearm into a's'eini-automatic 're'arniA A further object isto lprovide a gun barrel with a 'movable portion on the muzzle Yend operated by the forceof gas prssu'rein the barrel, ondischarge of the firearm, "for effecting automatic operation of the breech block mechanism'.

Other objects, features'a'nd'advantag'es ofthe invention will be Ymanifested in the following specification and drawing:

In the drawing:

Fig. 1 shows, partlyin section, 'a' side elevation of `the barrel portion of a'ifearm ih which a reciprocatingtubular magazine'transmits motion tothe'breech. The muzzle blastaotuated mechanism is in closed position. p

Fig. 2 shows the `ra`r`m of Fig. l'with vthe muzzie blast actuated mechanismm open position.

Fig. 3 shows 'an end view or the muzzle and muzzle blast mechanism.

Fig. 4 shows a modicati'onin wlfiichthe muzzle blast actuated parts'ar'e'coii'nected to a breech operating Vaction bar instead of"amovable`ina`g`a zine tube.

Fig. 5 is an 'enlarged'plan view'of the lconnecting rod of Fig.' 1.

Fig. 6 is an end viewof the'fore-end'oprated firearm of Fig.'4. t

Referring to r`Fig. 1, 'I' -rropresei'lts' the Ausualfgu'n barrel xedly connected to'the'forivad end of a receiver rII "and provided Ywith the usual'front and'rear sights Hand I3 respectively. The receivery I I contains the'well'known breech mechanism comprising, in part, a sliding breechblock Id, ringpin iii and' crossbary I6 of the magazine-action bar I'I; the 'crossbar y'I6 is provided with'a cam facei adapted,`on reloading ofthe firearm, to co''operate withth'ecain face I9 of the breech block I4. The tubular magazineaction bar I1 is of .well known construction Vhaving, in this instance,helicaliindentations ZU'for controlling the longitudinal 'movement of vsuccessive cartridges from the magazine vto thering chamber. The functions incidenti-)o reloading are effected by reciprocati'on ofthe magazine I1, as more fully describedinthepatent'to Pedersen, No. 1,044,568, November 19, 191'2. The rearward portion of the magazi'zieac'tion bar I1 slides'in a suitable aperture 'in vthe forward end of Athe receiver I I, and its forward'eridiis' slidably"sup"- ported by a hanger 2l suitably keyed' to the bot-i tom Yof the barrel il). The magazine vshowr'l and' described is Ithe pul'pOSe Of illustration only,

it being clear' that Yany magazine "oi similar 'form and action may be adapted 'tothe purpose of the present invention. A stop collar 22is secured to the forward end ofthe magazine by fastening means 23 so that vwhen the magazine 'is in 'its extreme forward position 'the collar 22 will abut the rear of they hanger 2|.

" purpose of this invention is' rmlyattached to the barrel 'I0 by suitable fastening means such as screws (not shown) received in tapped holes 21, 21, ofthe fixed hanger 25 and a lug 28, respectively, suitably secured to the barrel it. The

' attachment of the `fore-end to the barrel in 'this manner effects 'a housing 'for 'the unhampered reciprocation of the tubular magazine and the free end of the coil spring 2'4, within vthe longitudinal bore of the fore-end. At the forward end of the tubular magazine is a substantially solid block indicated generally by numeral 30, havinga cylindricalplug portion 3I s`eatedwithin the open end of the tubular magazine I'I and' secured therein by a suitable screw 32; it will be clear that any equivalent means for securingthe plugin theend of the magazine may be used. The forward end 'ofthe block 30'is bifurcatedso as to form two forwardly Vextending "parallel spaced lips or hinge members 33, between which a connecting rod 34 is pivotally supported at its rear end by pivot pin 3'5. The forward end 'of the' connecting rod '34 is enlarged in cross section as indicated in Figo and bifurcated as at B6, 3S so as to form a hinge Vconnection 5I with a downwardlyprojecting tonguetl vformed on the underside of a segmental'member or barrel portion 38 of a barrel sleeve indicated generally by numeral 39. The latter is an integral heavy walled cylindrical tube having'an end portion to whichv is bored to substantially the diameter of the barrel bore, and an over-bored skirt di, the forepart of which completely encircles the end of the barrel I0 as clearly shown in Figs. 1 and 3, while thefrearpa'rt is slottedto'form'afpair of spaced The collar 22 thus acts as a stop to limit the'forward' movement of" side plates 42, 42 (see Fig. 3) suitably bowed to conform to the barrel l of the firearm and having upwardly extending walls 43, 43 properly spaced to embrace opposite sides of the frontsight base or rib 44 which is integral with or secured to the forward end of the barrel I0. Suitable pins 45 are adapted to be driven through the walls 43, 43 and sight rib 44 to secure the sleeve 39 to the barrel. The downwardly extending spaced wall portions 46, 46 of the aforesaid side plates constitute hinge members between/.f

which one end of a lever arm 41 is pivotally supported, as at 48. The portion 40 of the sleeve 39, together with the arcuately surfaced portion 38, comprise, in effect, an extension of the gun barrel I0, being slightly larger in outside diameter but of substantially the same bore. 49 represents a gas chamber formed between the end of the gun barrel Il] and the rear face of the bore of the sleeve portion 40, the gas chamber being shaped, in cross section, substantially as a truncated cone, and including, in part, an inclined wall 50 adapted to act as a pressure surface for initiating the opening of the pivoted barrel portion 38. As shown in Fig. 3, a portion of the bottom wall of the sleeve 40 is cut or milled out to form a slot 52 somewhat wider than the width of the sleeve bore, and substantially one-half the sleeve depth. The aforementioned segmental member or barrel portion 38 is adapted to conform substantially, as shown, to the shape and dimensions of the milled out slot 52 and is displaceably mounted therein. To this end the segment 38 is integrally formed on the free end of the aforementioned pivoted arm 41, whereby pivotal movement of the latter radially displaces the barrel portion relative to the barrel sleeve 40.

It is believed clear that in the operation of the device the force of the expelled gases created by' the explosion will pivot the segmentalportion 38 downwardly about the pivot 48 of its pivot arm 41 and by the pivotal connection 5l causes the connecting rod 34 to move rearwardly, whereby the tubular magazine I1 will be retracted to its rearmost position against the restraining force of the spring 24. The magazine is associated with the breech mechanism in such a manner, for example, as described in the aforementioned patent to Pedersen, No. 1,044,568, that rearward movement of the magazine effectively actuates the breech block I4 and breech block mechanism whereby the gun is automatically reloaded. After the force effecting the rearward movement of the magazine has been dissipated in compressing the spring 24, the' force of compression of the latter returns the muzzle blast actuated elements to their original position whereby the breech is closed, and the gun is again ready to be fired.

Although the above description has related particularly to the adaptation of the device of this invention to a tubular magazine actuated breech block, it is to be clearly understood that the device may be readily used in connection with the action bar of any of the well known foreend operated firearms, such, for example, as the firearm shown in the patent to Loomis, No. 1,579,177, March 30, 1926. the muzzle blast mechanism to an action bar is illustrated in the modification shown in Figs. 4 and 6, in which 60 represents an action bar connected at its rear end to 'suitable breech block mechanism comprising, in part, the usual breech block 6l having a cam groove 62 engaged'by a' pin 63 carried on the extended end of the action The adaptation of bar 60, whereby reciprocation of the bar actu ates the breech block as more fully explained in the aforementioned Loomis patent. The forward end of the action bar 60 projects forwardly closely adjacent the outer walls of the barrel I0 and tubular magazine 64. It will be understood that the magazine 64 is fixedly mounted at its rear end in the `receiver ll and that its forward end is rigidly connected to the barrel I0 by suitable means, such as hanger 65 and release nut 66; consequently there will be no reciprocating movement of the magazine for reloading the arm.

'The reloading is done by reciprocation of the action bar 60 which in the usual practice is secured to and actuated by the usual reciprocating fore-end or hand grip 61. mln the present construction the fore-end 61 is xed to the barrel I0 as described in connection with the previous embodiment of the invention and the action bar'60 is extended through the fore-end 61 and reciprocates freely therein in a suitable groove 68 formed in the inner surface of the xed fore-end as shown in Fig. 6. A coil spring 69 is loosely mounted on the fixed tubular magazine 64. A collar 10 is slidably mounted on the magazine and is adapted to act as a stop or abutment for the forward end of the spring 69. A screw 1| or other suitable means is provided for fastening the action bar to one side of the collar 10, whereby rearward movement of the action bar will eect compression of the spring on the magazine 64. It will be understood that the rear end of the spring is held against movement relative to its freely movable front end by suitable means which, as shown, may comprise a second stop collar 12 suitably secured to the barrel I. As in the embodiment of the invention rst described, the spring effects a constant restraining force against rearward movement of the action bar 60 and is of suicient strength to return the breech block mechanism from its open position to its closed position. While the above description has been confined to the structure shown in Figs. 4 and 6, it will be clearly understood that the invention contemplates the use of any desired means for transmitting the motion of connecting rod 34 tothe breech. As shown in Fig. 4, the forward end of the action bar extends beyond the magazine supporting elements 65 and 66 and is provided with'a reverse bend as shown at 13 so as to be brought substantially into alignment with the hereinbefore described connecting rod 34 to which the forward end of the action bar 6i) is pivoted by a pin 14. The position of the reverse bend 13 in the forward end of the action bar 60 is such that the latter may be moved rearwardly without interference with the fixtures 65 and 66.

The operation of the above described modication is believed to be obvious from the previous description of one embodiment of the invention as given in connection with Figs. 1 and 2.

It will be understood that the constructions shown and described represent a desirable form of the invention for accomplishing the objects stated above but that these constructions are only for the purpose of illustrating the invention and are not limiting thereof as other modifications may be made without departing from the inven- 7o' tion as dened in the appended claims.

What is claimed is: 1. In a firearm comprising a'receiver; breech mechanism housed in said receiver; a barrel fixed tonsaid receiver; a'cylindrical sleeve concentric with the muzzle of said barrel; a gas chamber comprising an annular conicalv surface in the mouth of said sleeve adjacent the muzzle of said barrel; actuating means for said breech mechanism comprising a spring and a prismatic section of said gas chamber normally held in position concentric with said barrel by said spring and adapted to be displaced by gaseous pressure within said gas chamber; and connections from said prismatic section to said breech mechanism.

2. In a firearm comprising a receiver; breech mechanism housed in said receiver; a barrel fixed to said receiver; a cylindrical sleeve concentric to the muzzle of said barrel, said sleeve having a gas chamber comprising an annular conical surface in the mouth of said sleeve adjacent the muzzle of said barrel and a displaceable prismatic section; and actuating means for said breech mechanism comprising said displaceable prismatic section of said sleeve, a magazine tube reciprocable relative to said barrel and receiver assembly, means connecting said magazine tube to said breech mechanism, a spring carried on said tube, said spring being constructed and arranged to resist the displacement of said magazine tube and normally to hold the prismatic secsection; and actuating means for said breech mechanism comprising said displaceable prismatic section of said sleeve, a magazine tube fixed to said barrel and receiver assembly, an action bar, means for guiding said action bar on said tube, means connecting said action bar to said breech mechanism, a spring carried on said tube, said spring being constructed and arranged to engage said action bar guide means to resist the displacement of said action bar and normally to hold the prismatic section of said sleeve concentric with the barrel, said prismatic section being displaceable by gas pressure within said gas chamber, and a link connecting said prismatic section to the action bar.

4. In a rearm comprising a receiver; a breech mechanism housed in said receiver; a barrel fixed to said receiver having a front sight; a cylindrical sleeve concentric with the muzzle of said barrel, said sleeve comprising spaced upwardly extending walls adapted to cooperatively engage said `front sight for securing said sleeve to the muzzle of said barrel, a gas chamber comprising an annular conical surface in the mouth of said sleeve adjacent said barrel muzzle and a displaceable prismatic section pivotally supported on the underside of said sleeve; and actuating means for said breech mechanism comprising a spring and said prismatic section of said sleeve, the latter being normally held in position concentric with said barrel by said spring and adapted to be displaced by gaseous pressure Within said gas chamber and connections from said prismatic section to said breech mechanism.

CHARLES H. BARNES. 

